The present invention relates to document managing systems which manage documents, using a computer, and more particularly to a document retrieving method in a document managing system which manages and classifies a document managed by a computer, irrespective of a managing system for a file system of a computer.
At present, we use application programs such as word processor software and spreadsheet software on personal computers and work stations to create and manage documents.
Conventionally, those computers use a file system which is a subsystem of an operating system (OS) to manage documents in the form of a data file on the file system. For example, in a Microsoft Windows Operating System (trademark) sold by Microsoft Corporation, documents are managed hierarchically by a control file called a directory on a hierarchical file system which manages data files hierarchically. At this time, when a document is composed of a plurality of data files, like a text data file and a format data file, the form of the name of a file (the name of the file is used as the base name of the data file and an extension is attached to each of kinds of data files) and the name of the directory are caused to correspond to the name of the document in order to cause the document and the data files to correspond to each other to store those data files in that directory.
In order to cause a document and an application program to correspond to each other, there is, for example, a file manager, which is a program to manage a file system, in Microsoft Windows. The file manager has the function of causing an application program and a document to correspond to each other, using an extension of the name of the data file. When the data file is instructed to start up an application program, a corresponding application program is searched for on the basis of the extension of the data file and the data file is started up as data.
As another technique, Macintosh (trademark) sold by Apple Computer, Inc. stores information on an application program in each data file.
In order to classify and browse for documents, there is a technique which classifies documents in accordance with a directory, using a hierarchical file system. For example, a directory is named in correspondence to a classification, and a directory and a data file are constructed in the form of a tree structure in a hierarchical manner such that the user can fabricate a classification system freely and browse for stored documents by tracing the directory. At this time, in order to classify a document from different hierarchical directories, the Macintosh system uses the function of an alias of a file to put a special control file which refers to another data file in a directory of a different hierarchy to thereby create a plurality of classifications.